Improvement in steam-engines



2 Sheets--Sheet1.

W. C. WILCDX.

Steam-Engine. N0; 59,733 I Patented Feb. 9,1875.

nventor r'rEs WILLIAM C. WILCOX, OF SAN FRANCISCO, CALIFORNIA.

IMPROVEMENT IN STEAM-ENGINES.

Specification forming part of Letters Patent No. 1 59,733. datedFebruary 9, 1875; application filed June 1, 1874.

Direct-Acting Steam-Engines; and I do hereby declare the followingdescription and accompanying drawings are suflicient to enable anyperson skilled in the art or science to which it most nearly appertainsto make and use my said invention or improvement without furtherinvention or experiment.

My invention relates to certain improve: ments in direct-actingsteam-engines, which are provided with a main and supplementary valve,and a supplementary piston to operate the main valve; and it consists inthe employment of two ports for the admission of steam from the mainvalve-chamber to a point hehind the supplemental piston, for the purposeof cushioning this piston, and the combination of these ports with apassage in the valve itself, whereby the steam is supplied and cut 05 atthe proper points.

Referring to the accompanying drawing for a more complete explanation ofmy invention, Figure 1, Sheet 1, is a longitudinal vertical sectiontaken through :20 :12, Fig. 3. Fig. 2 is a longitudinal section throughy y. Fig. 3, Sheet 2, is atransverse vertical section through 2 2, Fig.l, also'showing a section of piston C. Fig. 4 is a plan view ofvalve-face. Fig. 5 is a top view of valve. A is the cylinder of myengine, and in a direct line above it is situated the cylinder 13 of thesupplemental piston C. This supplemental piston is cylindrical, and fitsits cylinder so as to move steam-tight from one end to the other, itslength being such as to necessitate a short stroke. In the center thispiston is made somewhat smaller, and the corners D D upon the main valveE fit between the end portion of the piston, so that the stroke of thepiston serves to move the valve E, and alternately open and close thesteam and exhaust ports for the main cylinder.

My supplemental piston, being cylindrical, is allowed to turn itselfinto any position, and consequently all portions of it will be equallysubjected to wear, and it will have a tendency to remain tight for along time.

In order to drive this piston C and the main valve, steam is admitted tothe ends alternately from the steam space or chamber which surrounds itscenter, and lies above and around the main valve. This is done by meansof a supplemental valve, F, which works in a chamber just at one side ofthe main valve-chamber. A slot or opening admits steam from the mainvalve-chamber to the center of the valve F, which consists of a cylinderhaving each end and the center fitted steam-tight, and united bysmallerportions, around which the steam can pass freely. An exhaust and steamport open into this valve-chamber at each side of the middle section ofthe valve, and, as the valve is moved, it allows steam to passalternately to one side and the other of the middle part, f, so as toenter the chamber and circulate around the smaller part or stem of thevalve. The steam-ports 1 t supply this admitted steam alternately to theends of the supplemental piston C, and the exhaust-ports j are alsoopened alternately from the opposite ends of the piston, in the usualmanner. This supplemental valve F is operated partly by means ofpeculiarly-constructed levers directly from the main piston, and partlyby steam, which is admitted to drive the main piston. The levers G G aremade as shown at Fig. 2, and are hung in open angular slots upon pins H,which are screwed through the side of the cylinder, just above the bore.The slots in which the levers are hung open freely into the ends of thecylinder, and also into the ends of the chamber of the valve F, and theyare made angularly, so that the levers stand radially from the center ofthe cylinder, in order to allow the piston to act in-a direct line uponthem, as will be necessary from their peculiar motion. The lower face,m, of the lever-arm is made concave, as shown, so that when the edge ofthe piston slides beneath it, the movement will be agradually-increasing one, and the valve will be started slowly, and movemore rapidly toward the finish. The end a of the lever, which restsagainst the end of the valve F, is made convex, so as to have a sort ofrolling contact with the valve as it is moved forward, and as the centerof motion 0 of the lever is set forward of a line between the ends, itwill be seen that the lever will have a sort of lifting motion as it ismoved. When the pressure is taken off the lower end of the lever, itwill fall back by its own weight and release the valve. In order tocushion the supplemental piston O, and prevent it from striking the endsof the chamber, I provide two ports, r 1', which open into the end ofthe chamber, and lead thence to the valve-face at one side of the mainvalve-ports P P. A small hole, S, is made through the main valve E, andas this valve is moved, it admits steam 1nto the ports 7 r alternately,just before the piston reaches the end of its stroke.

The operation of my engine will be as follows: Steam, being admitted tothe engine, will surround the central portion of the supplemental piston(J, and fill the space above the main valve E. The supplemental valve FF being thrown to one end of its chamber, steam will enter the chamberbetween the centerf and the end F, and from here will be allowed to passthrough the port 1' to one end of the supplemental piston 0, thusdriving it to the other end of its chamber, and carrying the valve Ewith it. The eXhaust-portj being also open, the steam from the other endof the supplemental piston will escape into the main exhaust-port h,until the piston O has nearly completed its stroke, when the portion fwill have closed the port 13 and allow the cushion to act. Meanwhile,the main valve E has opened the main steain-port P, and steam rushesinto the cylinder A, driving the main piston to the opposite end of thecylinder, where it acts upon the lower end of the lever G, and begins toforce the valve F back again. This closes the exhaust-port j, and atthis instant the valveE has moved so far as to open the cushion-port r.This admits a jet of steam before the supplemental piston, which arrestsits motion and cushions it. The return movements are made in the samemanner, and thus the engine works.

Having thus described my invention, what I'claim, and desire to secureby Letters Patent, is-

1. The ports 1" 7', opening into the ends of the supplementalpiston-chamber, and leadiu g to the main valveface, in combination withthe main valve, with its port S, for the purpose of admitting steam tocushion the supplemental piston, substantially as herein de scribed.

2. The valve F F, with its central enlargement f, in combination withthe single supplyport 0, for admitting steam to the center of the valve,and the steam-ports i, exhaust-ports j, and the operating-levers Gr,substantially as and for the purpose herein described.

In witness whereof I hereunto set my hand and seal. 1 y

WILLIAM CAMPBELL WILGOX. [L. s.]

Witnesses:

H. D. Bacon, (J. M. RICHARDSON.

